This counter reports the total bytes of ingress traffic on this PM instance that were remarked -- allowed through but flagged as exceeding the committed rate while still within the excess rate -- during a completed 15-minute window (for example 14:30-14:45). A growing count over that completed 15-minute interval means this service is regularly bursting above what it's contracted for, and because yellow-marked traffic is typically the first to be dropped elsewhere in the network under congestion, a persistently high value is an early warning of intermittent loss the customer may notice before this switch's own DroppedBytes counter ever moves. For example, a service that shows heavy yellow-byte volume within that completed 15-minute interval but little in the surrounding bins points squarely at a predictable, time-bounded burst, such as an evening video-streaming peak, briefly exceeding its committed rate.